Porous metal–organic gel assisted by l-tartaric acid ligand for efficient and controllable drug delivery

Abstract

A novel Al-based metal–organic gel (Al-MOG), as a stable and controllable drug carrier, is assembled from bridging L-tartaric and Al³⁺ ions using a simple solvothermal method. The reaction temperature and the ratio of metal ions and ligands are vital for the formation of the gel. Transmission electron microscopy (TEM) and N₂ adsorption measurements demonstrate the porous structure of Al-MOG, which exhibits Brunauer–Emmett–Teller (BET) surface area of 427.9 m² g⁻¹. The coordination between Al³⁺ and L-tartaric acid as well as non-covalent interactions could play a vital role in the formation of Al-MOG. Considering its large BET and excellent biocompatibility derived from low toxicity of the metal ions and the natural acid ligand, we further investigate the behaviors of Al-MOG for the controlled release of methyl salicylate (MS), an antimicrobial drug. The results of drug loading experiments show that the largest drug loading amount of MS reaches 31.8 wt%, whereas the release time of MS is over 600 min. In addition, the mouldability of Al-MOG further demonstrates its promising potential to act as a drug carrier.